
somewhere UNKNOWN.
And most likely...
Money Heist Season 3, Episode 2

takes a bullet to the face
from a person or persons UNKNOWN.
Breaking Bad Season 4, Episode 7

whose UNKNOWN provenance
jeopardizes
The Big Bang Theory Season 5, Episode 2

...between the UNKNOWN...
Westworld Season 2, Episode 6

with an UNKNOWN virus!
Money Heist Season 3, Episode 4